Home security systems are notoriously subject to both false alarms and missed alarms. Over 90% of home security alarms are reported to be false alarms. Missed alarms, from failure to turn the security system on, are estimated to occur 30% to 50% of the time. The principal failing of these systems is in the extra time and care required to disable security systems before entry and to enable them upon leaving.
Law provides more severe penalties for “Breaking and Entering” than for apparently non-forced entry. Further, forced entry is usually noisy and may result in unwanted attention. Would-be intruders can therefore be expected to first try passkeys, lock picks or like tests of lock integrity before generating evidence of forcible entry.
The acts of locking a door behind on leaving and unlocking it upon returning are relatively automatic behaviors, much easier to maintain than additional and often complex arming and disarming sequences required with current home security systems. There is a need, therefore, for a security system that automatically arms upon locking a conventional keyed door and automatically disarms upon unlocking that door. Further, there is a need to reliably detect and alarm upon lockset tampering and similar indicators of attempted illegal entry. These needs would ideally be filled by a device able to operate with existing mechanical locksets and with all alarm operations fully controlled by normal actuations of the existing lockset.